The use of wireless communication systems to provide telephony service has been seen to provide several advantages over conventional wireline networks. These advantages include speed of deployment, lower cost of installation, and reduced maintenance of outside plant.
Conventional cellular-like terminals can be used for providing fixed wireless access (FWA) as well as conventional mobile cellular telephony. However, in order to reduce costs it is advantageous to use terminals designed for fixed wireless access only. Cost savings can be achieved as such terminals do not require mobility (in the conventional cellular sense) and also can be larger as a result.
To reduce costs further, a fixed wireless access terminal can use existing cellular networks for providing telephony service and hence there is no need to deploy a separate FWA cellular system. Additionally, a FWA terminal can reuse the technology and components originally designed for conventional cellular service.
Systems have been described for interfacing a standard conventional wireline telephone to a radio transceiver to enable such a standard telephone (or other device) to use the cellular network for providing telephony service. Such an interface device for connecting a cellular radio transceiver to a conventional telephony device is not new. For example, U.S. Pat. No. 4,658,096, naming West et al as inventors, describes an interface arrangement for connecting a conventional telephone set to a cellular transceiver such that the cellular network can provide telephony service to such a telephone set. This patent describes an interface which includes means for automatically determining when the user of such a telephone set has finished dialling, as the concept for connecting a telephone to cellular transceiver was known in the "radio-patch" art. The above cited West patent is known in the art, and has been cited many times in subsequent patents dealing with further aspects of connecting a cellular transceiver to a telephony device. Such systems, which may be adequate for providing POTS (plain ordinary telephone service) service, do not adequately support more advanced features, for example, call management services provided by conventional land line networks.
Call management services (hereafter CMS) include, for example, Calling Number Delivery (CND), Message Waiting Indicator, Time of day delivery, Calling Line Identification (CLID), Dialable Directory Number (DN), Reason for Absence of DN, Reason for Redirection, Call Qualifier, Name of Calling Party and Calling Identity on Call Waiting (CIDCW) by means of messages sent to a telephone unit. CLASS.SM. (Bellcore trademark) which is compliant with GR-30-CORE (TR-NWT-000030), LSSGR: Voiceband Data Transmission Interface (hereby incorporated by reference, along with cited documents) is a known format for sending such messages. Using this method, the central office switch, with the aid of an appropriately configured subscriber line interface circuit, is able to send information to subscribers using some form of data modulation scheme. Of course other types of protocols can be used, and in this specification we will generally refer to these services as call management services.
Furthermore, advanced cellular systems, for example, IS54B, April 1992, EIA/TIA Cellular System Dual-Mode Mobile Station--Base Station Compatibility Standard (hereby incorporated by reference), also provide call management services/features. Thus, suitably equipped cellular terminals compatible with IS54B can receive and display, call management services information. However, the wireless protocols are not compatible with the land line call management services protocols. Thus, there exists a need for providing call management services features to a standard telephone which is coupled, via a suitable interface, to a wireless network.